Understanding Our Evidence Ratings

In the peptide space, evidence quality varies enormously between compounds. Semaglutide has data from trials involving tens of thousands of participants. BPC-157 has over 100 studies but nearly all in animal models. Some newer peptides have only a handful of cell culture experiments.

Treating these compounds as equally "studied" would be misleading. Our evidence rating system exists to give you an immediate, honest signal about how much confidence the scientific community can place in a compound's purported effects.

Strong — Multiple human randomized controlled trials with consistent results, or at least one large (n>500) well-designed RCT, or a meta-analysis of human trials. Compounds at this level have demonstrated effects in rigorous clinical settings. Examples: semaglutide, tirzepatide.

Moderate — Limited human data (1-2 small trials, pilot studies, or case reports) supported by consistent animal evidence. Some human signal exists, but the evidence is not yet definitive. Examples: Selank, Semax, Sermorelin.

Preliminary — Studied primarily in animal models with no meaningful human clinical data. Even extensive and consistent animal results earn only this rating because the translation from animal models to human benefit is inherently uncertain. Examples: BPC-157, TB-500, Epithalon.

Insufficient — Minimal published research of any type. May have only in-vitro (cell culture) data or very limited animal studies. Not enough evidence to draw even preliminary conclusions.

Important: A compound can have different evidence ratings for different uses. We assign per-use ratings where appropriate and an overall compound rating based on the strongest use case.

Not all studies are equal. Here is how we weigh different study types, from strongest to weakest:

Meta-analyses and systematic reviews synthesize results from multiple studies and represent the highest level of evidence when well-conducted. Human randomized controlled trials (RCTs) are the gold standard for individual studies — participants are randomly assigned to treatment or placebo, minimizing bias. Human observational studies, case series, and case reports provide useful data but cannot establish causation. Animal studies (in vivo) test compounds in living organisms but face the fundamental problem that rodent biology does not perfectly predict human responses. In-vitro studies (cell cultures) examine effects at the cellular level but are the furthest removed from real-world human biology.

When a compound has only animal evidence, no matter how extensive, it remains at the "Preliminary" level until human data emerges. This is not a judgment on the quality of the animal research — it reflects the well-documented reality that most compounds showing promise in animals fail to translate to humans.